According to Publication 526 of the Internal Revenue Service, cash donations to religious organizations are tax-deductible. Examples given in the publication include "churches, a convention or association of churches, temples, synagogues, mosques and other religious organizations." Since tithes are monetary gifts to a church, they are not subject to taxation by the IRS.
Charitable donations are claimed on IRS Form 1040, Schedule A, which allows taxpayers to make itemized deductions. The same form is used for deducting mortgage interest and property taxes. For the deductions to be justified, the total from all deductions must be greater than the standard deduction that all taxpayers receive without itemizing. The amount of the standard deduction is subject to change annually and is calculated based on things such as marital status, age and number of dependents, according to Publication 501 of the IRS. Standard deductions are higher for anyone who is blind or over the age of 65.
If there is a question about the tax-exempt status of an organization, the IRS website provides an exempt organizations select check tool. Taxpayers can use the tool to check the eligibility of an organization for receiving tax-deductible donations and verify that the group has filed the appropriate forms.